Learning to regulate one's emotions is a critical life skill. Failures to regulate are associated with impulse control problems, poor social functioning and psychiatric conditions such as borderline personality disorder. Adolescence is a critical time for studying emotion regulation because it is a period when 1) reactivity to social cues is high and interpersonal experiences are salient and influential, 2) emotions tend to be more extreme and short-lived, and 3) emotion regulation processes mature into tools that can buffer one against stressors through adolescence and beyond. Although it is known that social cognitive emotion regulation processes in adults are supported by partially overlapping prefrontal, temporal and subcortical systems, scant research has examined how these maturing neural systems interact in adolescence. Until normal development of emotion regulatory abilities is characterized and its underlying mechanisms are clarified, it will not be feasible to construct maximally effective and age-appropriate interventions that promote development of regulatory skills for the individuals who need these skills the most. Towards this end, I propose using a combination of methodologies from social and developmental psychology, as well as cognitive neuroscience, to achieve two specific aims. Aim 1 will be to map the development of emotion regulation mechanisms from early adolescence through young adulthood. This aim will use neuroimaging to identify the neural bases of cognitive reappraisal, a specific emotion regulation strategy, and reappraisal's effects at different points in adolescence. Aim 1 will also examine how an emotional stimulus's characteristics, specifically whether or not it contains social content, may impact one's ability to reappraise at different points in adolescence. Aim 2 will be to examine how appetitive self-regulatory ability and sensitivity to social rejection may account for variability in emotion regulation capacity both within and across developmental time points. Performance on a delay of gratification task that tends to positively predict wellbeing and responses to a social rejection sensitivity measure that tends to negatively predict wellbeing will be used to predict neural and behavioral responses on the cognitive reappraisal task to understand what tendencies enhance and diminish emotion regulation efficacy across adolescence. Combining these methods will allow me to test novel hypotheses about emotional and social development in adolescence, and how patterns of individual and developmental variation in subcortically-driven affective reactivity and prefrontal control abilities may indicate which individuals are at risk for maladaptive self-regulatory behaviors. Future work may build on this knowledge by constructing interventions for these at-risk individuals that could build emotion regulatory skills and potentially reduce their chances of developing mental illness. PUBLIC HEALTH RELEVANCE: There is growing evidence that adolescence is a critical time for the development of emotion regulatory abilities that may buffer one against stressors and mental health problems throughout the lifespan. Using a combination of behavioral and functional imaging methods, the proposed research aims to characterize the development of emotion regulatory mechanisms in adolescence and to identify dispositional and behavioral tendencies that may enhance or diminish emotion regulatory capacity. The ultimate goal of this work is to identify individuals who are at risk for developing mental health problems associated with emotion dysregulation and to determine what aspects of self-regulation could be targeted in future interventions at specific points in development.